With respect to complex surveillance systems, such as those found in gaming establishments, schools, and shopping malls, surveillance cameras are typically placed in transparent domes mounted in ceilings or other supports, such as on poles in a parking lot.
In these systems, camera operators typically use a joystick type control to effect pan and tilt movements of various controllable cameras of the system. Zoom, focus, and iris functions of lenses coupled to these cameras are typically controlled by a keypad having discrete keys marked with these functions. A video switching matrix selectively couples video outputs from the cameras to a plurality of monitors, with the switching matrix controlled through the use of the keypad. In addition to controllable cameras, the surveillance system may also include fixed cameras, such as those directed toward doors, elevators, money counting rooms, cashier stations and the like.
A typical surveillance application will have many more cameras than monitors, and fewer operators than monitors. As a result, many of the views being observed by cameras are not monitored or recorded. For example, there may be cameras in locations that are normally not occupied, as in a money counting room. Surveillance operators are often required to periodically examine these areas but their work loads often prevent them from being able to accomplish this task on a timely basis. While size of these systems and ratios of the number of monitors with respect to the number of cameras varies widely, in a gambling casino there may be something on the order of about 500 surveillance cameras selectively coupled to 30 monitors, with two to five operators controlling the system and observing the monitors.
In these gambling casinos and other installations, surveillance operators must be proficient with using the surveillance system and be thoroughly familiar with the layout of the areas being observed. A surveillance operator must, within a short period of time, be able to bring up on a monitor random views; such as particular slot machines or gaming tables, views of money counting rooms, etc. While operators are provided with lists or drawings of locations of cameras and the particular objects or areas of interest, there may be thousands of views from hundreds of cameras that are of concern to an operator. As such, when asked to view a randomly selected area not routinely viewed, an operator may experience difficulty in locating a listing or drawing of the area, identifying the appropriate camera, maneuvering the camera and bringing up the view on a monitor. This is an undesirable situation as a risk exists that some critical activity may not be timely located and viewed by the surveillance system.
Another concern of surveillance operators relates to the need for returning cameras to to their "parking views", which are typically critical locations, such as a view including an exit, and to which the camera should be returned after use. Here, due to the necessity of having to constantly watch a monitor and control cameras during surveillance operations, the task of returning a previously used camera to it's parking view becomes a burden, and can be done only intermittently by the operators. As a result, cameras may be left in random positions, meaning that the next time a camera in such a position is used, critical time may be lost acquiring the desired view, such as when observing a suspicious person or a view responsive to an alarm indication.
Controllable cameras in surveillance systems generally fall into three categories, 1) Inexpensive, manually operated, cameras only capable of movement responsive to manual pan, tilt, zoom, focus and iris commands from an operator, and which are the most common type, 2) More expensive, semi-automated cameras equipped with "preset" controls, which use servo mechanisms to position the camera to internally stored pan, tilt, zoom, focus, and iris positions. With this data, a plurality of "preset" views for each camera may be stored in the camera and used to direct the respective camera to a one, or a sequence, of these preset views responsive to operating a key on the keypad, and 3) very expensive cameras containing computers capable of complex operations such as communicating information to the camera control system.
For cameras with preset capability, the number of preset views is set for each camera, such as 32 for one widely used camera. When there are hundreds of cameras equipped with preset capability, there may be thousands of preset views. As a result of the difficulty in remembering names and locations of this quantity of preset views, surveillance operators often do not use the preset capability to its full advantage, preferring instead to simply pan or tilt a camera to locations which they wish to view.
At the present time, a typical installation will have an architect's CADD (computer assisted drafting and designing) drawing available that contains information, such as in floor plans, wherein objects in the drawings are represented graphically and located with great precision. Generally, objects in these drawings are constructed as a series of lines, circles, or other geometrical shapes, each of which scaled to size using X and Y Cartesian Coordinates, with these drawing files known as "vector" format files. In most drawings, such as those of gambling casinos, there are many objects in the CADD floorplan that are represented by the same graphical outline, such as slot machines, which symbols being stored by the CADD program in a manner so as to not repetitively generate the symbol in memory. This is done by creating one image of the symbol in vector format and including in the image a reference point for locating the symbol in the drawing. This single image with a reference point is commonly known as a "component", with a typical drawing including a number of differing components. As such, after the image of the component is generated, it is only necessary to store a component reference name, rotation and scaling information, and coordinates, or "vectors" at which the reference point in the component is located in order to regenerate the object as many times as necessary. Once located in a CADD drawing, These individual objects are commonly known as "entities".
The CADD drawing and symbols therein may be converted and stored in several formats, two of which having gained considerable acceptance being the DXF and PCX formats. The PCX format, developed by PC PUBLISHER, is supported by most CADD programs, and is simply a bit mapped format where intensity and color values of each pixel making up an image is stored as a map in a digital format. The DXF format, developed by AUTODESK, stores coordinates of the drawing in an ASCII vector format, which is recognized by most, if not all, CADD programs. Thus, the majority of CADD drawings or selected elements therein can be converted by their respective programs to both the PCX and DXF formats from their native, usually proprietary formats.
Prior art of which Applicant is aware includes U.S. Pat. No. 4,992,866, issued to Morgan on Feb. 12, 1991. This reference discloses a camera control system requiring a number of computer controlled cameras, i.e. cameras that generate position information at the pan, tilt, zoom and focus motor drives and provide this information as feedback signals to operate the cameras in a closed loop configuration. These closed loop feedback signals are used in conjunction with a diagram that a user references to control movements of selected cameras. A conventional touch screen monitor and video switching matrix, under control of a microprocessor, provides a user with several options for selecting a particular camera, view, and monitor from a particular graphical representation.
While this system provides a relatively simple way to use a touch screen to effect camera, view, and monitor selection, it is limited in that it requires an operator to select from a predefined list of fixed views, or "assets" located in the diagram, which are similar to presets. Further, there is no ability to select an arbitrary location to view, or to refer to entities to be viewed by name, as is found in a CADD drawing. Further yet, there is no disclosure in Morgan as to how the graphical representations relate to camera movement, or how these graphical representations are constructed. In addition, there is no capability for the system to monitor the camera video, or relate portions of the video to locations on the diagram.
Another reference, U.S. Pat. No. 5,111,288, issued to Blackshear on May 5, 1992, discloses a feedback signal operated, closed loop camera system in conjunction with computer control used to store in memory one or more predetermined "presets", or views of particular interest. Computer routines are provided for controlling camera movements from one preset to another preset. Additional computer routines are provided for immediately moving a camera to view a preset responsive to an alarm.
Again, the system of Blackshear requires "smart" cameras with feedback position information of the pan and tilt mechanisms, with the attendant high cost of the cameras. Also, as each preset and sequence of presets must be manually entered into the computer, the system lacks the versatility needed for a large surveillance operation, such as found in a gambling casino.
To date, Applicant is unaware of any attempt to develop a surveillance camera control system wherein cameras are controlled in an open loop configuration (without requiring position feedback signals) by a data processor using a coordinate system, such as found in CADD drawings, for referencing camera movement. Further, Applicants system utilizes data from conventional CADD drawings for the purpose of operating surveillance cameras and monitors more effectively than is possible with methods of the known prior art.
Accordingly, it is a broad object of this invention to provide open loop control of surveillance cameras in conjunction with a coordinate system for referencing camera movement. In addition, numerous capabilities are provided that makes the system extremely flexible, and particularly useful in a system involving a number of large areas where numerous objects are to be monitored using a large number of cameras.